This umbrella protocol is used in the study of a variety of patients with disorders of mineral metabolism. During this past year we studied two groups of individuals, one being a series of patients with osteoporosis who have high turnover bone loss, hypercalciuria and elevated circulating levels of interluekin-ll. Another major group we studied was an extended family with markedly elevated bone mass. In addition the protocol continues to be used to study patients with X-linked hypophosphatemic rickets and other unusual metabolic bone disorders.